Bicycle-gearing.



.nls

Prien..

ATENT `FREI) STEINKAMI, OF BETHANY, CALIFORNIA.

BICYCLE-GEARING.

SJPECFICATION forming part of Letters Patent No. 716,129, dated December 16, 1902.

L Application led August 2,1902. Serial No. 118,113. (No model.)

obtain an increase of speed upon level ando good roads and a corresponding increase in power and decrease in speed upon steep or bad roads.

The object of the invention is to provide an exceedingly cheap, simple, and efficient means for accomplishing this variation in speed without removing any nuts or bolts or without making any change in the drivechains except to shift the said chain from oneW side of said sprockets to another.

Theinven tion consists also in the novel features of construction and combination, all of which will be fully described hereinafter and pointed out in the claims.

In the drawings forming part of this specication, Figure l is a side elevation illustrating the crank-hangerand drive-sprockets constructed and arranged in accordance with my invention.` Fig. 2`is a horizontal sectional view taken through the crank-hanger and showing the novel manner of journaling the crank-shaft therein. Fig'. 3 is a vertical sectional view showing the eccentric arrangement of the crank shaft within the crankhanger. Fig. lis a side elevation showing the cylinder shiftedso as to throw the crankhanger to its rearmost position. Fig. 5 is a detail perspective View of the catch. 'Fig. 6 is a detail perspective View showing the end of the lever. Fig. 7 is a detail View showing the head of the cylinder and the lever connected thereto. Fig. 8 is a detail perspective view of the cylinder.

\ In carrying out my invention I employ a crank-hanger A, which `is connected to the y bicycle-frame in the usual manner, and fitting snugly within the said crank-hanger is a cylinder B, the heads B of which have openings B2 produced eccentrically therein,

and secured in the said eccentric openings is thesleeve C,in which the crank-shaftD is journaled. The bearingsleeve C may be composed of any desirable number of parts provided with the usual ball-bearing devices.

A sprocket E is mounted upon the crankshaft D,said sprocket being a double sprocket, one toothed rim E being larger than the other toothed rim E2, and consequently provided with a larger number of teeth, the larger rim being employed when speed is desirable and the smaller rim being employed when power is desired more than speed. The sprocket F upon the rear axle is also double, the smaller one, F', being adapted for use in connection with the larger sprocket-rim of the Wheel E,'while the larger one,`F2,` is ad apted for use in connection with the smaller rim E2 of the sprocket E, it being understood that the diameters of said sprockets are such that one chain can be used upon both sets of sprockets without making any changes or alterations in the said chain. In order to slacken the chain, so as to shift it from one set of sprockets to another, I propose to move the crank-shaft rearwardly, and inorder to do this it is only necessary to turn the cylinder in the crank-hanger, inasmuch as the sleeve` carrying the crank-shaft iseccentrically arranged in the said sleeve B. In order to accomplish this movement of the cylinder,

`Ifprovide a lever G, which is rigidly connected to one of the cylinder-heads and is provided with a spring-actuated latch Gf at its free end which is adapted to engage a catch G2, depending from the rear horizontal member of the frame. A suitable guide-finger GS is arranged parallel with' the catch for the purpose of guiding and holding,r the lever and its spring-latch in connection with the catch. When the lever is held in engagement with the catch, the crank-shaft will be held to its foremost position,and consequently the drivechain will be held taut, and when it is desired to slacken the chain the lever is disengaged from the catch and moved around to the position shown in Fig. 4f, thus shifting the crank-shaft, and with it the sprocket E, to their lowermost position, and at each time the chain can be readily transferred from one set of sprockets to the other. After the chain ICO ' has been adjusted the lever is turned back,

carrying with it the cylinder, and consequently the crank-shaft and sprocket.

It will thus be seen that I provide an exceedingly cheap, simple, and efiicient construction, whereby a variable-speed drivinggear is produced, and one in which the variation can be accomplished without removing any bolts or nuts or Without making any change in the drive-chain.

Having thus fully described my invention,

what I claim as new, and desire to secure by Letters Patent, is-

l. The combination with a crank-hanger, of a cylinder mounted to turn therein, the crank-shaft journaled eccentrcally in the said cylinder, a lever connected to the said cylinder whereby the cylinder is turned, and a catch adapted to engage and hold the lever in a locked position for the purpose specified.

2. The combination with a crank-hanger, of a cylinder adapted to turn therein, a sleeve farranged eccentricall'y in the cylinder, the

crank-shaft journaled in the said sleeve, a

double sprocket mounted on the crank-shaft, a double sprocket mounted upon thel rear axle, the drive chain connecting the said sprockets, the lever connected to one end of the cylinder, a spring-actuated latch carried by the said lever and the catch arranged upon FRED STEINKAMP.

Witnesses:

F. O. I-loUsKEN, WM. C. BRAASCH. 

